title: Biochar mitigates negative effects of salt additions on two herbaceous plant species.
abstract: Addition of pyrolyzed biomass ("biochar") to soils has commonly been shown to increase crop yields and alleviate plant stresses associated with drought and exposure to toxic materials. Here we investigate the ability of biochar (at two dosages: 5 and 50 t ha(-1)) to mitigate salt-induced stress, simulating road salt additions in a factorial glasshouse experiment involving the broadleaved herbaceous plants Abutilon theophrasti and Prunella vulgaris. Salt additions of 30 g m(-2) NaCl to unamended soils resulted in high mortality rates for both species. Biochar (Fagus grandifolia sawdust pyrolyzed at 378 °C), when applied at 50 t ha(-1) as a top dressing, completely alleviated salt-induced mortality in A. theophrasti and prolonged survival of P. vulgaris. Surviving A. theophrasti plants that received both 50 t ha(-1) biochar and salt addition treatments showed growth rates and physiological performance similar to plants without salt addition. Biochar treatments alone also substantially increased biomass of P. vulgaris, with a ∼50% increase relative to untreated controls at both biochar dosages. Biochar did not significantly affect photosynthetic carbon gain (Amax), water use efficiency, or chlorophyll fluorescence (Fv/Fm) in either species. Our results indicate that biochar can ameliorate salt stress effects on plants through salt sorption, suggesting novel applications of biochar to mitigate effects of salinization in agricultural, urban, and contaminated soils.
authors.affiliation: Faculty of Forestry, University of Toronto, 33 Willcocks St., M5S 3B3 Canada. Electronic address: sc.thomas@utoronto.ca.
authors.forename: Sean C
authors.initials: SC
authors.lastname: Thomas
authors.forename: Susan
authors.initials: S
authors.lastname: Frye
authors.forename: Nigel
authors.initials: N
authors.lastname: Gale
authors.forename: Matthew
authors.initials: M
authors.lastname: Garmon
authors.forename: Rebecca
authors.initials: R
authors.lastname: Launchbury
authors.forename: Natasha
authors.initials: N
authors.lastname: Machado
authors.forename: Sarah
authors.initials: S
authors.lastname: Melamed
authors.forename: Jessica
authors.initials: J
authors.lastname: Murray
authors.forename: Alexandre
authors.initials: A
authors.lastname: Petroff
authors.forename: Carolyn
authors.initials: C
authors.lastname: Winsborough
mesh_terms: D002606:Charcoal / Q000008:administration & dosage / Q000378:metabolism*; D004787:Environmental Pollution / Q000517:prevention & control*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D019660:Malvaceae / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D009864:Ontario; D010788:Photosynthesis / Q000187:drug effects; D031347:Prunella / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D011897:Random Allocation; D012965:Sodium Chloride / Q000633:toxicity*; D012989:Soil Pollutants / Q000633:toxicity*; D013312:Stress, Physiological
chemical_list: D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal; D012965:Sodium Chloride
keywords: Biochar; Fertilization; Plant stress; Road salt; Salinization; Waste management